2 NaNVO3 + Cu0 + 2 H2SO4 CuIISO4 + Na2SO4 + 2 NIVO2 + 2 H2O

This is an oxidation-reduction (redox) reaction:

Cu0 - 2 e- CuII (oxidation)

2 NV + 2 e- 2 NIV (reduction)

Change the oxidation states